KR102427146B1 - Touch sensor substrate, touch panel, display device, and method for manufacturing touch sensor substrate - Google Patents

Abstract

A base material having a first electrode arrangement surface that is an example of a first surface, and a first electrode that is an example of a plurality of electrodes positioned on the first surface, wherein each of the plurality of first electrodes is the first surface a bottom surface in contact with, a top surface exposed from the first surface and opposite to the bottom surface, a surface exposed from the first surface and a side surface connecting the bottom surface and the top surface, the bottom surface and the top surface At least one and the said side surface are blackening layer BL.

Description

A touch sensor substrate, a touch panel, a display device, and a manufacturing method of a touch sensor substrate {TOUCH SENSOR SUBSTRATE, TOUCH PANEL, DISPLAY DEVICE, AND METHOD FOR MANUFACTURING TOUCH SENSOR SUBSTRATE}

The present invention relates to a touch sensor substrate having an electrode, a touch panel, a display device, and a method of manufacturing the touch sensor substrate.

BACKGROUND ART In recent years, touch sensors have been employed in operation units of various electronic devices including cellular phones, portable information terminals, ATMs, and car navigation systems. A touch sensor is an input device which detects the contact position of a fingertip or a pen tip, and is bonded on the display surface of image display panels, such as a liquid crystal display device. A touch sensor is classified into various types, such as a resistive film type, a capacitive type, an optical type, an ultrasonic type, according to the difference of the structure and detection method of a touch sensor, and is divided and used according to the use in an electronic device. Among them, from the viewpoint of excellent durability, transmittance, sensitivity, stability, and positional resolution, the electrostatic capacitive type in which electrodes do not contact each other is the mainstream of touch sensors.

Capacitive touch sensors include a surface type and a projection type, but in either type, it is a technology applied to the fact that capacitive coupling occurs when something with electrostatic conductivity, such as a finger, approaches the surface of the touch sensor, electrodes and fingertips. A touch sensor grasps the capacitive coupling between them, and detects a position (refer patent document 1, for example).

A surface-type touch sensor is provided with the transparent conductive film which spreads planarly on a transparent base material as an electrode for position detection, and is equipped with the electrode connected to a drive circuit at four corners of the conductive film.

A projection type touch sensor is provided with a plurality of sensor conductive films extending along one direction, an X direction, and a plurality of first conductive films extending along a Y direction orthogonal to the X direction as electrodes for position detection. . Such an electrode for a position detection has a mesh shape in planar view, for example, and the detection precision of a position is high, so that the arrangement pitch of the conductive film for sensors and the arrangement pitch of the conductive film for 1st use are small.

On the other hand, since the touch sensor mentioned above is provided in the display surface of the panel for image display in many cases, light transmittance is calculated|required also in any type of touch sensor. From the viewpoint of such light transmittance, the material for forming the electrode for position detection is preferably a transparent conductive material with high transparency such as ITO or ZnO, but the electrode formed of the transparent conductive material as the size of the touch sensor progresses The length is large, and as a result, the resistance of the electrode itself is high, and the detection sensitivity of the position is low. Therefore, in recent years, a metal with high conductivity while blocking light is used for the forming material of the electrode for position detection, and the shape of the electrode itself is made into a thin wire, and the proposal which raises the aperture ratio of a touch sensor is made.

Further, the connection terminal, which is an end portion of the electrode, is bonded to the connection terminal portion of the flexible substrate on which the driving semiconductor element is mounted via an ACF (Anisotropic conductive film) or the like. At this time, even if the forming material of the electrode is a transparent conductive material such as ITO, the connection terminal connected to the electrode is usually formed of or covered with a metal in order to lower the contact resistance. In this regard, it is also possible to form the electrode and the connection terminal at the same time as long as the material for forming the electrode is a metal.

By the way, when the forming material of the electrode is a metal having light-shielding property, and the shape of the plurality of electrodes is, for example, a mesh shape in a plan view, the electrode is not visible until, for example, 10 μm or less, the thickness of the electrode is It is necessary to make the line width small. And in order to suppress that the electrode which is a thin wire is visually recognized, it is necessary to suppress the reflective luster peculiar to a metal (for example, refer patent documents 2 - 4).

Japanese Patent No. 4610416 Japanese Patent Laid-Open No. 2014-16944 Japanese Patent Laid-Open No. 2014-19947 Japanese Patent Laid-Open No. 2013-129183

However, since the process of suppressing the reflective luster peculiar to a metal is a process which raises the resistance value of an electrode, if such a process is performed to the whole electrode, the resistance value of an electrode will rise to the range which is not permissible as a touch sensor.

An object of the present invention is to provide a method for manufacturing a touch sensor substrate, a touch panel, a display device, and a touch sensor substrate capable of suppressing the visibility of the electrode by reducing the increase in the resistance value of the electrode.

A touch sensor substrate for solving the above problems includes a substrate having a first surface and a plurality of electrodes positioned on the first surface. And, each of the plurality of electrodes has a bottom surface in contact with the first surface, a top surface exposed from the first surface and opposite to the bottom surface, a surface exposed from the first surface, the bottom surface and the It is a blackening layer which is a surface layer and the side surface which connects a top surface, At least one of the said bottom surface and the said top surface, and the said side surface are provided with the said blackening layer which comprises the surface of the said blackening layer.

In the touch sensor substrate, the surface resistivity of the blackening layer is preferably less than 1Ω/□.

The said touch sensor board|substrate WHEREIN: It is preferable that the thickness of the said blackening layer is 0.2 micrometer or less.

The said touch sensor board|substrate WHEREIN: It is preferable that the reflectance of the said blackening layer is less than 20% in the visible region of 400 nm or more and 780 nm or less.

A touch panel for solving the above problems includes: a sensor base including a plurality of first electrodes, a plurality of second electrodes, and a transparent dielectric layer sandwiched between the plurality of first electrodes and a plurality of the second electrodes; A cover layer covering the sensor body, and a peripheral circuit for measuring an electrostatic capacitance between the first electrode and the second electrode are provided. The touch panel includes the above-described touch sensor substrate, and at least one of the first electrode and the second electrode is the electrode included in the above-described touch sensor substrate.

A display panel that solves the above problem includes a display panel that displays information, a touch panel that transmits the information displayed by the display panel, and a driving circuit that drives the touch panel. In addition, the said touch panel is the above-mentioned touch panel.

A method of manufacturing a touch sensor substrate for solving the above problems is a step of forming a plurality of metal electrode patterns on a substrate having a first surface, wherein each of the plurality of electrode patterns includes a bottom surface in contact with the first surface and and a top surface exposed from the first surface and facing the bottom surface, and a surface exposed from the first surface and provided with a side surface connecting the bottom surface and the top surface. Further, each of the plurality of electrode patterns is subjected to a blackening treatment of any one of a sulfurization blackening treatment and a substitution blackening treatment, and at least one of the bottom surface and the top surface and the side surface are replaced with a blackening layer which is a surface layer. do.

In the method of manufacturing the touch sensor substrate, the blackening treatment is performed by immersing the electrode pattern in a blackening treatment liquid, which is a solution containing Pd ions, by a substitution reaction between a metal constituting the electrode pattern and the Pd ions. It is a substitution blackening treatment of forming a blackening layer in the electrode pattern, the temperature of the blackening treatment liquid is 55° C. or less, the time the electrode pattern is immersed in the blackening treatment liquid is 120 seconds or less, and the blackening layer is It is preferable that the thickness is set to a length of 0.2 µm or less.

In the manufacturing method of the said touch sensor board|substrate, the temperature of the said blackening process liquid is 35 degreeC or more and 55 degrees C or less, Pd concentration in the said blackening process liquid is 100 ppm or more and 500 ppm or less, and in the blackening process liquid It is preferable that pH is 1.5 or more and 2.5 or less, the time for which the electrode pattern is immersed in the blackening treatment liquid is 10 seconds or more and 120 seconds or less, and the thickness of the blackening layer is set to a length of 0.2 µm or less.

In the method of manufacturing the touch sensor substrate, the time period for which the electrode pattern is immersed in the blackening treatment liquid is preferably set to a length such that the change in the line width of the electrode pattern before and after the blackening treatment is 0.3 μm or less. do.

ADVANTAGE OF THE INVENTION According to the touch sensor board|substrate in this invention, a touch panel, and a display device, it can reduce that the resistance value of an electrode becomes high, and the visibility of the electrode with which a touch sensor board|substrate is equipped can be suppressed.

1 is a plan view showing an example of a planar structure of a display device according to an embodiment;
Fig. 2 is a cross-sectional view showing an example of a cross-sectional structure of a display device according to an embodiment;
Fig. 3 is a cross-sectional view showing another example of the cross-sectional structure of the display device according to the embodiment;
Fig. 4 is a cross-sectional view showing another example of the cross-sectional structure of the display device according to the embodiment;
Fig. 5 is a block diagram showing an example of the electrical configuration of the touch panel according to the embodiment;
Fig. 6 is a circuit diagram showing another example of the electrical configuration of the touch panel according to the embodiment;
It is sectional drawing which shows an example of the cross-sectional structure of the sensor base|substrate in one Embodiment.
Fig. 8 is a cross-sectional view showing another example of the cross-sectional structure of the sensor body according to the embodiment;
Fig. 9 is a cross-sectional view showing another example of the cross-sectional structure of the sensor body according to the embodiment;
Fig. 10 is a cross-sectional view showing another example of the cross-sectional structure of the sensor body in the embodiment;
It is sectional drawing which shows an example of the cross-sectional structure of the electrode wire in one Embodiment.
12A to 12E are process diagrams viewed in cross section for explaining a method for manufacturing a touch sensor substrate according to an embodiment.
Fig. 13 is a graph showing the relationship between reflectance and wavelength in an electrode pattern according to an embodiment, and is a graph showing reflectance before blackening treatment and reflectance after blackening treatment;

An embodiment of a method of manufacturing a touch sensor substrate, a touch panel, a display device, and a touch sensor substrate will be described with reference to FIGS. 1 to 13 .

[Flat structure of display device]

A configuration of the display device will be described with reference to FIG. 1 . In addition, in FIG. 1, for convenience of explaining the configuration of the first electrode and the second electrode included in the display device, the plurality of first electrodes constituting the electrode group and the plurality of second electrodes constituting the electrode group are exaggerated. have. Moreover, the 1st electrode line which is an example of the electrode which comprises a 1st electrode, and the 2nd electrode line which is an example of the electrode which comprises a 2nd electrode are shown typically.

As shown in FIG. 1 , the display device is a laminate in which, for example, a display panel 10 , which is a liquid crystal panel, and a sensor body 20 are joined together by a single transparent adhesive layer, and to drive the sensor body 20 . A driving circuit is provided for A display surface 10S is partitioned on the surface of the display panel 10, and information such as an image based on external image data is displayed on the display surface 10S. In addition, as long as the relative positions of the display panel 10 and the sensor body 20 are fixed by other structures such as a housing, the transparent adhesive layer may be omitted.

The sensor body 20 constitutes a capacitive touch panel. The sensor base 20 is a laminate in which the electrode substrate 21 and the cover layer 22 are joined by a transparent adhesive layer 23 , and has light transmittance through which information displayed by the display panel 10 is transmitted. The cover layer 22 is made of a glass substrate or a resin film, and the surface of the cover layer 22 opposite to the surface to which the transparent adhesive layer 23 is bonded is the surface of the sensor base 20 . , further functions as the operation surface 20S of the sensor body 20 . The transparent adhesive layer 23 has light transmittance which transmits the image displayed on the display surface 10S, and a polyether adhesive or an acrylic adhesive is used for the transparent adhesive layer 23, for example.

Among the components constituting the electrode substrate 21, the transparent support substrate 31, the first electrode 31DP, the transparent adhesive layer 32, the transparent dielectric substrate 33, The second electrode 33SP is positioned.

The transparent support substrate 31 constituting the electrode substrate 21 is superimposed on the entire display surface 10S formed on the display panel 10 and transmits information such as an image displayed by the display surface 10S. has a The transparent support substrate 31 is composed of, for example, a substrate such as a transparent glass substrate or a transparent resin film, and may be a single-layered structure composed of one substrate, or a multilayered structure in which two or more substrates are superimposed.

A surface of the transparent support substrate 31 opposite to the surface facing the display panel 10 is set as the first electrode arrangement surface 31S on which the first electrode 31DP is formed. The first electrode arrangement surface 31S of the transparent support substrate 31 is an example of the first surface, and in the first electrode arrangement surface 31S, each of the plurality of first electrodes 31DP has one direction. It has a band shape extending along the Y direction, and is arranged at intervals along the X direction orthogonal to the Y direction. In addition, the transparent support substrate 31 which is an example of a base material is comprised from a transparent base material and an adhesive layer, and the 1st electrode mounting surface 31S may be the surface of the adhesive layer to which the 1st electrode 31DP is adhere|attached. One touch sensor substrate is constituted by the transparent support substrate 31 and the first electrode 31DP.

Each of the plurality of first electrodes 31DP is a set of the plurality of first electrode lines 31L, and each of the plurality of first electrode lines 31L has a linear shape extending along one direction. Each of the plurality of first electrodes 31DP is individually connected to the selection circuit via the first pad 31P, and is selected by the selection circuit by receiving a drive signal output by the selection circuit.

Copper, aluminum, and silver nanowires, which are metals with low resistance, are used as the material for forming the first electrode 31DP, but copper is preferable. In addition, if the forming material of the first electrode 31DP is a transparent conductive material such as ITO, on the premise that the resistance of the first electrode line 31L is within a predetermined range, the line width of the first electrode line 31L can be thickened. have. On the other hand, if the material for forming the first electrode 31DP is a material having light-shielding properties such as metal, in order to increase the transmittance of the first electrode 31DP, the material for forming the first electrode line 31L is a transparent conductive material. Compared with , it is preferable that the line width of the first electrode line 31L is thin and the number of the first electrode line 31L is small. In addition, the space|interval of 31 L of 1st electrode lines adjacent to each other is suitably set so that a desired position resolution may be acquired.

The connection portion SD, which is a portion located outside the plurality of first electrodes 31DP in the first electrode arrangement surface 31S, is a portion where wirings, terminals, etc. are formed, and these wirings and terminals include a driving semiconductor A connection terminal of the mounted flexible substrate is connected to the first electrode 31DP. Further, even when the material for forming the first electrode 31DP is a transparent conductive material such as ITO, for the material for forming the wiring or terminal formed in the connecting portion SD, a metal is employed from the viewpoint of high adhesion to the connecting terminal. Or, there are many cases where parts made of metal are placed side by side. Therefore, with the configuration comprising the above-described first electrode 31DP, it is possible to form wirings and terminals formed on the connection portion SD at the same timing as that of the first electrode 31DP, so that the pattern in the connection portion SD Compared to a manufacturing method in which the formation of , and the formation of the first electrode 31DP are performed separately, there is an advantage in that the manufacturing process is simplified.

The plurality of first electrodes 31DP and the portion where the first electrode 31DP is not located in the first electrode arrangement surface 31S is bonded to the transparent dielectric substrate 33 by a single transparent adhesive layer 32 . has been The transparent adhesive layer 32 has light transmittance for transmitting information such as an image displayed on the display surface 10S, and includes a first electrode arrangement surface 31S, a plurality of first electrodes 31DP, and a transparent dielectric substrate ( 33) is attached. For the transparent adhesive layer 32, for example, a polyether-based adhesive, an acrylic adhesive, or the like is used. A plurality of first electrodes 31DP are arranged on the back surface of the transparent dielectric substrate 33 which is the surface opposite to the transparent support substrate 31 .

The transparent dielectric substrate 33 is composed of, for example, a transparent resin film such as polyethylene terephthalate or a substrate such as a transparent glass substrate, and may have a single-layer structure composed of one substrate, or a multilayer structure in which two or more substrates are superimposed on each other. may be The transparent dielectric substrate 33 has light transmittance for transmitting information such as an image displayed on the display surface 10S, and a relative permittivity suitable for detecting an electrostatic capacitance between electrodes.

The surface of the transparent dielectric substrate 33 opposite to the transparent adhesive layer 32 is set as the second electrode arrangement surface 33S on which the second electrode 33SP is formed. The second electrode arrangement surface 33S of the transparent dielectric substrate 33 is an example of the first surface, and in the second electrode arrangement surface 33S, each of the plurality of second electrodes 33SP extends along the X direction. It has an extended strip|belt shape, and is lined up with a space|interval along the Y direction orthogonal to an X direction. In addition, the transparent dielectric substrate 33 which is an example of a base material is comprised with a transparent base material and an adhesive layer, and the 2nd electrode arrangement surface 33S may be the surface of the adhesive layer to which the 2nd electrode 33SP is adhere|attached. One touch sensor substrate is constituted by the transparent dielectric substrate 33 and the second electrode 33SP.

Each of the plurality of second electrodes 33SP is a set of a plurality of second electrode lines, and each of the plurality of second electrode lines 33L has a linear shape extending along a direction orthogonal to the first electrode line 31L. have it Each of the plurality of second electrodes 33SP is individually connected to a detection circuit via the second pad 33P, and a current value is measured by the detection circuit.

Although copper, aluminum, and silver nanowire which are metals with low resistance are used for the forming material of the 2nd electrode 33SP, copper is preferable. In addition, if the forming material of the second electrode 33SP is a transparent conductive material such as ITO, on the premise that the resistance of the second electrode line 33L is within a predetermined range, the line width of the second electrode line 33L can be thickened. have. On the other hand, if the material for forming the second electrode 33SP is a material having light-shielding properties such as metal, in order to increase the transmittance of the second electrode 33SP, the material for forming the second electrode line 33L is a transparent conductive material. Compared with , it is preferable that the line width of the second electrode line 33L is thin and the number of the second electrode line 33L is small. In addition, the gap|interval of 33L of 2nd electrode lines adjacent to each other is suitably set so that a desired position resolution may be acquired.

The connection portion SS, which is a portion located outside the plurality of second electrodes 33SP in the second electrode arrangement surface 33S, is a portion in which wirings, terminals, etc. are formed, and these wirings and terminals include a driving semiconductor A connection terminal of the mounted flexible substrate is connected to the second electrode 33SP. In addition, even when the forming material of the second electrode 33SP is a transparent conductive material such as ITO, for the forming material of the wiring and the terminal formed in the connecting portion SS, a metal is employed from the viewpoint of high adhesion to the connecting terminal. Or, there are many cases where parts made of metal are placed side by side. Therefore, if it is the structure of the above-mentioned second electrode 33SP, since it is possible to form the wiring and the terminal formed in this connection part SS at the same timing as the second electrode 33SP, the pattern in the connection part SS Compared with a manufacturing method in which the formation of , and the formation of the second electrode 33SP are performed separately, there is an advantage in that the manufacturing process is simplified.

In a plan view opposite to the second electrode arrangement surface 33S, each of the plurality of first electrodes 31DP three-dimensionally intersects each of the plurality of second electrodes 33SP. Thereby, the some 1st electrode line 31L with which each of the some 1st electrode 31DP is equipped, and the some 2nd electrode line 33L which each of the some 2nd electrode 33SP are equipped with are, A lattice pattern having a lattice shape in which unit lattices having a rectangular shape are aligned in a plan view opposite to the two electrode arrangement surface 33S is formed.

The plurality of second electrodes 33SP and the portion where the second electrode 33SP is not located in the second electrode arrangement surface 33S is bonded to the cover layer 22 by the transparent adhesive layer 23 described above. have.

[Cross-section structure of display device]

As shown in FIG. 2 , among the components constituting the sensor body 20 , the transparent support substrate 31 , the first electrode 31DP, the transparent adhesive layer 32 , A transparent dielectric substrate 33 , a second electrode 33SP, a transparent adhesive layer 23 , and a cover layer 22 are positioned. Among them, the transparent dielectric substrate 33 is sandwiched between the plurality of first electrodes 31DP and the plurality of second electrodes 33SP. The sensor body 20, the selection circuit, and the detection circuit constitute an example of a touch panel.

In addition, the transparent adhesive layer 32 covers the periphery of each of the first electrode lines 31L constituting the first electrode 31DP, and fills the spaces between the first electrode lines 31L adjacent to each other, the first electrode 31DP and It is located between the transparent dielectric substrates (33). In addition, the transparent adhesive layer 23 covers the periphery of each second electrode line 33L constituting the second electrode 33SP, and fills the spaces between the second electrode lines 33L adjacent to each other, the second electrode 33SP and It is located between the cover layers 22 . These components WHEREIN: At least one of the transparent adhesive layer 23 and the transparent support substrate 31 may be abbreviate|omitted.

In addition, among the components constituting the display panel 10 , a plurality of components constituting the display panel 10 are sequentially arranged from the component distant from the sensor body 20 as follows. That is, from the component distant from the sensor body 20, the lower polarizing plate 11, the thin film transistor (hereinafter, TFT) substrate 12, the TFT layer 13, the liquid crystal layer 14, the color filter layer 15, A color filter substrate 16 and an upper polarizing plate 17 are located.

In addition, in the above-described display device, as shown below, some of the components may be omitted, and the order in which the components are positioned may be changed.

That is, as FIG. 3 shows, in the electrode substrate 21 which comprises the sensor base|substrate 20, the transparent support substrate 31 and the transparent adhesive layer 32 may be abbreviate|omitted. In this configuration, among the surfaces of the transparent dielectric substrate 33 , one surface facing the display panel 10 is set as the first electrode placement surface 31S, and the first electrode placement surface 31S is provided with the first An electrode 31DP is positioned. Then, the second electrode 33SP is positioned on the surface of the transparent dielectric substrate 33 opposite to the first electrode arrangement surface 31S. This first electrode 31DP is formed by, for example, patterning of one thin film formed on the first electrode arrangement surface 31S, and the second electrode 33SP is also, for example, the second electrode 33SP. ) is formed by patterning a single thin film formed on the surface where it is located.

Alternatively, as shown in FIG. 4 , in the sensor base 20 , the first electrode 31DP, the transparent support substrate 31, the transparent adhesive layer 32, and the transparent A dielectric substrate 33 , a second electrode 33SP, a transparent adhesive layer 23 , and a cover layer 22 are positioned. In this configuration, for example, the first electrode 31DP is formed on the first electrode arrangement surface 31S, which is one surface of the transparent support substrate 31 , and the second electrode 33SP is formed on the transparent dielectric substrate 33 . It is formed on one surface of the second electrode arrangement surface 33S. A surface of the transparent support substrate 31 opposite to the first electrode placement surface 31S and a surface of the transparent dielectric substrate 33 opposite to the second electrode placement surface 33S are the transparent adhesive layer 32 . ) is attached by Further, a transparent dielectric layer is constituted by the transparent support substrate 31 , the transparent adhesive layer 32 , and the transparent dielectric substrate 33 .

[Electrical configuration of touch sensor]

Referring to FIG. 5 , an electrical configuration of the touch sensor will be described. In addition, below, as an example of a capacitive touch sensor, the electrical structure in a mutual capacitive touch sensor is demonstrated.

As FIG. 5 shows, the touch sensor is equipped with the sensor body 20, the selection circuit 34, the detection circuit 35, and the control part 36. As shown in FIG. The selection circuit 34 is connected to the plurality of first electrodes 31DP, the detection circuit 35 is connected to the plurality of second electrodes 33SP, and the control unit 36 includes the selection circuit 34 and the detection circuit ( 35) is connected.

The control unit 36 generates and outputs a start timing signal for starting the generation of the driving signal for each first electrode 31DP to the selection circuit 34 . The control unit 36 generates a scan timing signal for sequentially scanning the target to which the drive signal is supplied from the first first electrode 31DP toward the n-th first electrode 31DP by the selection circuit 34 , print out

The control unit 36 generates and outputs a start timing signal for initiating the detection circuit 35 to detect the current flowing through each second electrode 33SP. The control unit 36 generates and outputs a scanning timing signal for sequentially scanning the detection circuit 35 from the first second electrode 33SP toward the n-th second electrode 33SP.

The selection circuit 34 starts generation of the drive signal based on the start timing signal output from the control unit 36 , and sets the output destination of the drive signal to 1 based on the scan timing signal output from the control unit 36 . Scanning is performed from the first electrode 31DP1 at the n-th to the first electrode 31DPn at the n-th.

The detection circuit 35 includes a signal acquisition unit 35a and a signal processing unit 35b. The signal acquisition unit 35a starts acquisition of a current signal that is an analog signal generated in each of the second electrodes 33SP based on the start timing signal output by the control unit 36 . Then, the signal acquisition unit 35a selects the current signal acquisition source from the first second electrode 33SP1 to the n-th second electrode 33SPn based on the scan timing signal output by the control unit 36 . inject towards

The signal processing unit 35b processes each current signal acquired by the signal acquisition unit 35a to generate a voltage signal that is a digital value, and outputs the generated voltage signal to the control unit 36 . In this way, the selection circuit 34 and the detection circuit 35 generate a voltage signal from a current signal that changes according to a change in the capacitance, thereby changing the capacitance between the first electrode 31DP and the second electrode 33SP. measure The selection circuit 34 and the detection circuit 35 are examples of peripheral circuits.

The control part 36 detects the position where a user's fingertip etc. touched in the sensor body 20 based on the voltage signal outputted by the signal processing part 35b. At this time, since the arrangement of the first electrode 31DP and the second electrode 33SP is a mesh (matrix) arrangement, the position of the fingertip in the X direction and the position of the fingertip etc. in the Y direction are in each direction. independently detected in

In addition, although the electrical configuration of the mutual capacitive touch sensor has been described as an example of the capacitive touch sensor, the above-described electrical configuration of the touch sensor can also be embodied as a self-capacitive touch sensor. Hereinafter, the electrical configuration of the self-capacitance type touch sensor will be described. Further, in the self-capacitance touch sensor, the detection range of the first electrode 31DP and the detection range of the second electrode 33SP are different from each other, while the detection range of the first electrode 31DP is different from each other. Since the detection method and the detection method in the second electrode 33SP are the same as each other, the detection method will be described by exemplifying the second electrode 33SP.

A driving semiconductor element (power supply) is connected to both sides of each second electrode 33SP via a connection terminal. Fig. 6 schematically shows this state.

As shown in FIG. 6 , the AC signal 24 of the same phase and the same voltage is applied to both sides of the second electrode 33SP. Since the voltages at both ends are the same, normally, no current flows through the second electrode 33SP. From this state, when a finger having conductivity and capacitance approaches the second electrode 33SP, a capacitive coupling 23B occurs between the second electrode 33SP and the finger. When the capacitive coupling 23B occurs, a closed circuit is formed through a person so that an alternating current flows through the second electrode 33SP. At this time, since a current flows through the second electrode 33SP, the resistance of the second electrode 33SP is preferably low.

The current flowing through the second electrode 33SP flows toward the capacitive coupling 23B from both sides of the second electrode 33SP through the semiconductor element, and how much current flows from either side of the second electrode 33SP ), depending on the location where the capacitive coupling occurred. In addition, there is a feature that how much current flows from either side does not depend on the impedance at which the second electrode 33SP is approached or contacted. Since the current flowing into the second electrode 33SP can be predicted from the voltage by putting resistance elements (not shown) at both ends of the second electrode 33SP, from that information, the second electrode of the capacitive coupling 23B The position on (33SP) is calculated.

By arranging these second electrodes 33SP along the Y direction, and arranging the first electrodes 31DP whose position can be detected similarly to the second electrode 33SP along the X direction, the position in the two-dimensional direction is determined. It functions as a position sensor that can detect it. In this principle, even if a plurality of contacts occur at the same time, it is possible to specify the respective contact positions.

In addition, whether a touch sensor employing a mutual capacitive method or a touch sensor employing a self-capacitance method increases the positional resolution by making the mesh thinner. On the other hand, since the image of the operation surface 20S is visually recognized through the grid|lattice comprised by the 1st electrode line 31L adjacent to each other, and the 2nd electrode wire 33L adjacent to each other, the visibility of an image is improved by making a mesh coarse. . In addition, the function as a sensor can be discussed in terms of a configuration comprising one first electrode 31DP and one second electrode 33SP. Although 31 L of 1st electrode lines and 33 L of 2nd electrode lines are linear normally, you may bend in zigzag like a broken line shape, a sine wave shape, and a square wave shape, for example.

[Cross-sectional structure of the sensor body 20]

Hereinafter, examples of the cross-sectional structure of the sensor body 20 including the cross-sectional structure shown in FIGS. 2 to 4 will be described in detail.

As shown in FIG. 7 , in one example of the cross-sectional structure of the sensor base 20 , the first electrode line 31L is disposed on the transparent support substrate 31 , and the second electrode line is disposed on the transparent dielectric substrate 33 . (33L) is arranged. At this time, the surface on which the first electrode line 31L is formed in the transparent support substrate 31 is the first electrode arrangement surface 31S, and the surface on which the second electrode line 33L is formed in the transparent dielectric substrate 33 . Silver is the 2nd electrode arrangement surface 33S. Then, as the arrangement of the first electrode line 31L and the second electrode line 33L with respect to the transparent dielectric substrate 33, the second electrode line 33L is arranged on the surface of the transparent dielectric substrate 33, and the transparent dielectric substrate ( 33), the first electrode line 31L is arranged. That is, when viewed from the observer side, the back side is the second electrode line 33L, and the back side is the first electrode line 31L. In addition, the sensor base|substrate 20 which has such a cross-sectional structure is included in the cross-sectional structure of the display apparatus demonstrated in FIG. 2, for example, the transparent support substrate 31 in which the 1st electrode line 31L was formed, and the 2nd electrode wire. The transparent dielectric substrate 33 on which 33L is formed is formed by bonding through an adhesive layer between the substrates. In addition, the transparent support substrate 31 which is an example of a base material is comprised from a transparent base material and an adhesive layer, and the 1st electrode mounting surface 31S may be the surface of the adhesive layer to which the 1st electrode 31DP is adhere|attached. In addition, the transparent dielectric substrate 33 which is an example of a base material is comprised from a transparent base material and an adhesive layer, and the surface on which the 2nd electrode line 33L was formed may be the surface of the adhesive layer to which the 2nd electrode wire 33L is adhere|attached.

As shown in Fig. 8, in another example of the cross-sectional structure of the sensor body 20, the transparent dielectric substrate 33 includes a first transparent dielectric substrate 33A and a second transparent dielectric substrate 33B, have. The first electrode line 31L is disposed on the first transparent dielectric substrate 33A, and the second electrode line 33L is disposed on the second transparent dielectric substrate 33B. At this time, in the first transparent dielectric substrate 33A, the surface on which the first electrode line 31L is formed is the first electrode arrangement surface 31S, and in the second transparent dielectric substrate 33B, the second electrode line 33L This formed surface is the second electrode arrangement surface 33S. Then, as the arrangement of the first electrode line 31L and the second electrode line 33L with respect to the transparent dielectric substrate 33, the second electrode line 33L is arranged on the surface of the transparent dielectric substrate 33, and the transparent dielectric substrate ( 33), the first electrode line 31L is arranged. That is, when viewed from the observer side, the second transparent dielectric substrate 33B on which the second electrode line 33L is formed and the first transparent dielectric substrate 33A on which the first electrode line 31L is formed are stacked in a front-to-back relationship. In addition, the sensor base 20 having such a cross-sectional structure includes a first transparent dielectric substrate 33A included in the cross-sectional structure of the display device described in FIG. 4, for example, on which the first electrode lines 31L are formed; The second transparent dielectric substrate 33B on which the second electrode line 33L is formed is formed by bonding through an adhesive layer between the substrates. Moreover, the 1st transparent dielectric substrate 33A which is an example of a base material is comprised from a transparent base material and an adhesive layer, and the 1st electrode arrangement surface 31S may be the surface of the adhesive layer to which the 1st electrode line 31L is adhere|attached. In addition, the second transparent dielectric substrate 33B, which is an example of the substrate, is composed of a transparent substrate and an adhesive layer, and the second electrode arrangement surface 33S may be the surface of the adhesive layer to which the second electrode wire 33L is adhered.

As shown in FIG. 9 , in another example of the cross-sectional structure of the sensor base 20 , the first electrode line 31L is disposed on the transparent support substrate 31 , and the second electrode line is provided on the transparent dielectric substrate 33 . (33L) is arranged. At this time, the surface on which the first electrode line 31L is formed in the transparent support substrate 31 is the first electrode arrangement surface 31S, and the surface on which the second electrode line 33L is formed in the transparent dielectric substrate 33 . Silver is the 2nd electrode arrangement surface 33S. Then, as the arrangement of the first electrode line 31L and the second electrode line 33L with respect to the transparent dielectric substrate 33, the second electrode line 33L is arranged on the surface of the transparent dielectric substrate 33, and the transparent dielectric substrate ( 33), the first electrode line 31L is arranged. In addition, the sensor body 20 having such a cross-sectional structure is included in the cross-sectional structure of the display device described in FIG. 2 .

As FIG. 10 shows, in another example of the cross-sectional structure of the sensor base 20, 31 L of 1st electrode lines are arrange|positioned on the transparent support substrate 31, and the insulating resin layer which covers the 1st electrode lines 31L. A second electrode line 33L is disposed at 31I. At this time, in the transparent support substrate 31, the surface on which the 1st electrode line 31L is formed is the 1st electrode arrangement surface 31S, The surface on which the 2nd electrode line 33L is formed in the insulating resin layer 31I. Silver is the 2nd electrode arrangement surface 33S. Then, as the arrangement of the first electrode line 31L and the second electrode line 33L with respect to the insulating resin layer 31I, the second electrode line 33L is arranged on the surface of the insulating resin layer 31I, and the insulating resin layer ( 31L), the 1st electrode line 31L is arrange|positioned. If it is such a structure, since the base material of a touch sensor is thin, weight reduction of a touch sensor is achieved. In addition, as each example to FIGS. 7-9 shows, if the 1st electrode line 31L and the 2nd electrode line 33L are the structure which are separately formed in the front and back of a board|substrate, since the board|substrate itself is insulating, such an insulating resin layer (31I) is unnecessary.

By the way, since an electrode formed of a metallic material exhibits metallic luster on the surface, unlike an electrode formed of a transparent conductive material, the reflected light from the electrode is greater than the reflected light from the transparent electrode, and the electrode provides a transparent contrast of the displayed image. While lowering than the electrode, the electrode itself is easily visually recognized.

In this regard, at least one of the first electrode 31DP and the second electrode 33SP described above includes the blackening layer BL as a surface layer of the electrode. The blackening layer BL is provided in the surface exposed from the surface in which an electrode is formed among the surfaces which the electrode provided with it has. Blackening layer BL is a layer which does not show metallic luster, and is especially located in the side surface part which is obliquely seen among the surfaces which the electrode provided with it has. 11 shows an example in which the blackening layer BL is provided in the first electrode 31DP.

As FIG. 11 shows, the 1st electrode 31DP is equipped with the blackening layer BL on the surface exposed from the 1st electrode arrangement surface 31S among the surfaces which the 1st electrode 31DP has. The blackening layer BL is a surface layer in which metallic luster is suppressed, and is located on the side surface 31SW of the first electrode 31DP viewed in the oblique direction among the surfaces of the first electrode 31DP. The position of the blackening layer BL reaches a site|part other than the side surface 31SW among the surfaces which the 1st electrode 31DP has other than the side surface 31SW.

For example, if the cross-sectional shape of the first electrode 31DP is a rectangle, the blackening layer BL has a bottom surface 31TS and a first portion in contact with the first electrode arrangement surface 31S other than the side surface 31SW. The electrode 31DP is provided on at least one of the top surface 31KS opposite to the bottom surface 31TS.

The blackening layer BL is formed by performing the blackening process which is a process which reduces surface reflection with respect to the surface of the conductive film 31B which comprises the 1st electrode 31DP. The line width of the first electrode 31DP including the blackening layer BL is the electrode width W31, and the line width of the bulk portion of the first electrode 31DP that maintains the composition of the conductive film 31B even after the blackening treatment is the bulk width W31B , and the width obtained by subtracting the bulk width W31B from the electrode width W31 is the blackening width. In suppressing the high resistance by formation of blackening layer BL, it is preferable that the thickness of blackening layer BL is 0.2 micrometer or less, and it is preferable that the change of the line|wire width in before and behind blackening process is 0.3 micrometer or less.

In addition, the structure in which the blackening layer BL is located on the bottom surface 31TS other than the side surface 31SW is formed by transferring the 1st electrode 31DP to which the blackening process was previously performed to the 1st electrode arrangement surface 31S. In addition, the configuration in which the blackening layer BL is located on the top surface 31KS other than the side surface 31SW is formed by subjecting the first electrode 31DP formed on the first electrode arrangement surface 31S to the blackening treatment.

In the structure in which the blackening layer BL is located on both the bottom surface 31TS and the top surface 31KS other than the side surface 31SW, the first electrode 31DP subjected to the blackening treatment in advance is the first electrode arrangement surface 31S. It is formed by performing a blackening treatment on the top surface 31KS of the transferred first electrode 31DP. Among these structures, the structure shown in FIG. 11 is an example in which the blackening layer BL is provided on the side surface 31SW and the top surface 31KS. That is, the structure which coat|covers all the surfaces of the 1st electrode 31DP except the part which is in contact with the 1st electrode arrangement surface 31S with the blackening layer BL is employ|adopted.

In this way, in the configuration in which the blackening layer BL is not provided on the bottom surface 31TS, in the configuration in which the bottom surface 31TS faces the viewer, the first electrode 31DP is compared to the configuration in which the blackening layer BL is provided on the bottom surface 31TS. ), since the reflectance is high, the visibility of the electrode is also increased. At this time, for example, as shown in FIG. 7 , an increase in reflectance is suppressed by bonding at the back-distal portion, but interfacial reflection accompanying the step difference of the electrode occurs not to a small extent. Therefore, in a configuration in which the blackening layer BL is not provided on the bottom surface 31TS, a configuration in which the top surface 31KS faces the observer is preferable as shown in FIG. 10 .

In addition, in the configuration in which the blackening layer BL is not provided on the top surface 31KS, in the configuration in which the top surface 31KS is positioned to face the observer, the first electrode 31DP is compared to the configuration in which the blackening layer BL is provided on the top surface 31KS. ), since the reflectance is high, the visibility of the electrode is also increased. Therefore, in the configuration in which the blackening layer BL is not provided on the top surface 31KS, as shown in FIG. 8 , a configuration in which the back portions are joined so that the bottom surface 31TS faces the observer is preferable.

As described above, according to the configuration in which at least one of the top surface and the bottom surface and the side surface of the electrode are the surface of the blackening layer BL, metallic luster is suppressed in the surface that is seen in the oblique direction among the surfaces of the electrode. And since this blackening layer BL is the surface layer of an electrode, in the bulk of an electrode, the low resistance value which a metal has is maintained, As a result, it is possible to reduce the resistance value of an electrode from becoming high, and to suppress the visibility of an electrode. .

[Method for manufacturing the sensor body 20]

Hereinafter, the manufacturing method of the sensor body 20 is demonstrated.

First, a conductive film for forming the first electrode 31DP is formed on the surface of the substrate. Then, the conductive film formed on the surface of the substrate is processed by electrode patterning according to the shape of the plurality of first electrodes 31DP. And the blackening process is performed to the electrode pattern used as the object in which the blackening layer BL is formed, and the touch sensor board|substrate provided with the 1st electrode 31DP is formed.

In addition, a conductive film for forming the second electrode 33SP is formed on the surface of the substrate. Then, the conductive film formed on the surface of the base material is processed into an electrode pattern corresponding to the shape of the plurality of second electrodes 33SP. And the touch sensor board|substrate provided with the 2nd electrode 33SP is formed by blackening process being given to the electrode pattern used as the object in which blackening layer BL is formed.

Subsequently, the first electrode 31DP and the second electrode 33SP are disposed so that the transparent dielectric substrate 33 is positioned between the first electrode 31DP and the second electrode 33SP, and the above-described sensor base ( 20) is prepared.

For example, the touch sensor board|substrate shown in FIG. 7 is obtained by bonding the back part of the base material after blackening process, and the distribution part of the base material after blackening process via an adhesive layer, for example. Moreover, the touch sensor board|substrate shown in FIG. 8 is obtained by bonding the base material after blackening process in front-back relationship via an adhesive layer, for example. Furthermore, the 1st electrode 31DP is formed in the back part of one base material, and the touch sensor board|substrate shown in FIG. 9 is obtained by forming the 2nd electrode 33SP in the back part of the base material. Moreover, an insulating layer is laminated|stacked on the 1st electrode 31DP after black processing, and a conductive film, such as copper foil for forming the 2nd electrode 33SP using this as a base material, is laminated|stacked on the insulating layer. Then, the conductive film formed on the insulating layer is patterned on the plurality of second electrodes 33SP, and the second electrode 33SP after the patterning is subjected to black processing, whereby the touch sensor substrate shown in FIG. 10 is obtained.

At this time, the base material on which the first electrode 31DP is formed is appropriately selected according to the cross-sectional structure of the sensor base 20 described above, and may be the transparent support substrate 31 , the transparent dielectric substrate 33 , or may be transparent. A transfer substrate which is a substrate for transferring an electrode to the support substrate 31 or the transparent dielectric substrate 33 may be used. The substrate on which the second electrode 33SP is formed is also appropriately selected according to the cross-sectional structure of the sensor substrate 20 described above, and may be the transparent support substrate 31 , the transparent dielectric substrate 33 , or the transfer substrate. may be In addition, the base material may be comprised only with a transparent base material, may be comprised from a transparent base material and an adhesive layer, and the 1st electrode 31DP and the 2nd electrode 33SP may be formed in a transparent base material, and may be formed in an adhesive layer.

A glass substrate, a resin substrate, or a film base material is used for the base material with which an electrode is formed, for example. Among these glass substrates, resin substrates, and film substrates, a film substrate is preferable from the viewpoint of low cost and light weight. As a film base material, polyethylene terephthalate (PET), polycarbonate (PC), a cycloolefin polymer (COP), a cyclic olefin copolymer (COC), etc. are used. The thickness of a film base material is suitably set in the range of 20 micrometers or more and 200 micrometers or less, for example.

As the conductive film processed into the electrode pattern, a single layer film composed of a single metal such as copper or aluminum (Al), or a laminate film such as Mo (molybdenum)/Al/Mo can be used. From the viewpoints of low resistance of the electrode and easy manufacture of the electrode, the electrode forming material is most preferably copper. It is preferable that the laminated|multilayer film of Mo/Al/Mo etc. be used as an ITO side electrode. As a method of forming such a conductive film on a substrate, any one of direct film formation by a vapor deposition method, a sputtering method, etc., an electrolytic method, bonding of rolled metal foil, etc. is applied.

In the vapor deposition method, a material such as a metal such as copper or aluminum or a metal oxide is vaporized or sublimed in a vacuum container for accommodating a transparent substrate, and the vaporized or sublimated material is applied to the surface of the transparent substrate spaced apart from the material serving as the vapor deposition source. A thin film is formed by attaching it. In the sputtering method, a target is installed in a vacuum container accommodating a transparent substrate, sputtering gases such as rare gas, nitrogen, and oxygen are ionized in the vacuum container, and the ionized particles collide with a target to which a high voltage is applied. Then, a thin film is formed by attaching atoms emitted from the surface of the target to the surface of the transparent substrate. In the electrolytic method, metal ions are electrodeposited on the surface of a transparent substrate in a solution in which metal ions are dissolved. As a method of forming an electrode on the surface of a transparent base material, any of these methods can be employ|adopted. The thickness which an electrode has is suitably set based on the electrical conductivity requested|required of an electrode, and the line|wire width requested|required of an electrode, and is set to 0.1 micrometer or more and 20 micrometers or less, for example.

At least one of metal plating such as chrome plating and nickel plating, sulfurization blackening treatment, oxidation blackening treatment, substitution blackening treatment, and roughening blackening treatment is used for the blackening treatment, and among these treatments, the resistance value of the electrode is A preferable method is selected from the viewpoint of suppressing the rise and from the viewpoint of lowering the reflectance of the electrode.

In the sulfiding blackening treatment, for example, hydrogen sulfide, which is a decomposition product by heating of sulfur contained in cystine and methionine, which are amino acids contained in egg white, and iron contained in egg yolk react to produce iron sulfide exhibiting blue or black color. This blackening is a reaction seen also in metal elements such as copper and zinc instead of iron contained in egg yolk, and by immersing the electrode pattern in an appropriate sulfiding solution for blackening the electrode pattern, the color of the surface of the electrode pattern is blue. or turn black.

Oxidation blackening changes the color which the surface of an electrode pattern shows to black by oxidizing the surface of an electrode pattern and producing|generating a metal oxide on the surface of an electrode pattern.

The substitution blackening process is to substitute another metal atom for the metal atom which comprises the surface of an electrode pattern. This substitution is a reaction utilizing the difference in electrode ionization tendency between the metal atoms constituting the surface of the electrode pattern and other metal atoms. That is, when a metal having a large ionization tendency is immersed in an aqueous solution containing a metal ion having a small ionization tendency, the metal having a large ionization tendency is dissolved to become a metal ion and release electrons. When this electron reduces a metal with a small ionization tendency, a metal with a small ionization tendency is precipitated. For example, when the material forming the electrode pattern is copper, the metal having a large ionization tendency is copper, and a metal ion having a smaller ionization tendency than copper is selected, whereby a substitution reaction occurs.

A roughening blackening process is a process which forms minute unevenness|corrugation on the mirror-shaped metal surface, and reduces the reflectance of a metal surface, and is also called soft etching. As an example of a roughening blackening process, the chemical process of immersing an electrode pattern in chemical liquids, such as an acidic solution, or the physical process of sputtering the surface of an electrode pattern is mentioned.

[Example 1]

An embodiment of a method of manufacturing a touch sensor substrate will be described with reference to FIGS. 12A to 12E . In addition, since the method of forming the first electrode 31DP and the method of forming the second electrode 33SP are almost the same, hereinafter, the second electrode 33SP is formed on the substrate on which the second electrode 33SP is formed. An example of obtaining a touch sensor substrate by forming will be described. In Fig. 12, an example in which an electrode group arranged in a stripe shape is made of PET by applying a photolithography method using PET with an electrolytic copper foil bonded to one side is described, but the electrodes constituting the electrode group The film forming method of a pattern is not limited to bonding of foil.

As shown in Fig. 12(a) , a PET sheet having a thickness of 50 µm was used as the substrate.

As Fig. 12(b) shows, on the PET sheet, an electrolytic copper foil 33R having a thickness of 3 µm was laminated and adhered. Then, after wash|cleaning the copper foil surface, the acrylic negative resist layer was laminated on the electrolytic copper foil 33R. Thereafter, the acrylic negative resist layer was exposed to ultraviolet rays having an exposure intensity of 100 mJ through a mask having a stripe pattern. Then, the acrylic negative resist layer was developed with a mixed aqueous alkali solution of sodium carbonate (Na ₂ CO ₃ ) and sodium hydrogencarbonate (NaHCO ₃ ), and a part of the underlying copper foil was exposed by removing unnecessary resist.

As FIG.12(c) shows, the copper foil partly covered with the acrylic negative resist layer is immersed in the ferric chloride solution whose liquid temperature is 60 degreeC, and the exposed part in copper foil is removed by etching. did. And the 2nd electrode 33SP which is an electrode pattern arrange|positioned in stripe shape was obtained by peeling the remaining resist layer with an alkali solution.

As FIG.12(d) shows, the sulfiding blackening process which is one of blackening processes was implemented to the electrode pattern. At this time, a solution containing sodium sulfide (Na ₂ S) and potassium chloride (K ₂ S) in a concentration of 0.02 or more and 1% or less was used as a coloring liquid (ammonium chloride solution) as sulfidation components. And the PET sheet on which the electrode pattern was formed was repeatedly immersed in the ammonium chloride solution. Accordingly, copper sulfide (CuS) was deposited on the surface of the second electrode 33SP, and the surface of the electrode pattern was gradually discolored from blue light to black light. Then, an electrode having a reflectance of less than 20% in the visible region (400 nm or more and 780 nm or less) and having a blue color as a color was obtained. The blackening layer BL which has a thickness of 0.2 micrometer by this patterning and blackening process of copper foil was obtained. The surface resistivity of the 2nd electrode 33SP which has such blackening layer BL, ie, the surface resistivity of blackening layer BL, was less than 1 ohm/square.

On the other hand, in the state in which the surface of the electrode showed black indicating convergence of the sulfurization reaction, the surface resistivity of the electrode was a high value of several 10 Ω/square. The thickness of the blackening layer BL in this case was about 0.25 micrometer or more. From these results, in reducing the increase in the resistance value in the electrode, the treatment time for the sulfurization treatment is preferably in the range where the thickness of the blackening layer BL is 0.2 μm or less, and the surface of the electrode pattern is blue. range is preferred.

In addition, the covering state of the blackening layer BL shown in FIG.12(d) is typical, so that the line width of the 2nd electrode 33SP is narrow, the shape of the 2nd electrode 33SP is the rounding-processed fish paste shape. As shown, in the second electrode 33SP, it becomes difficult to distinguish between the side surface and the top surface.

As FIG.12(e) shows, the protective layer PL for protecting the 2nd electrode 33SP was coated on the surface of the 2nd electrode 33SP containing blackening layer BL, and the touch sensor board|substrate was obtained. After forming the electrode group on the base material, it is preferable to cover the electrode with the protective layer PL in order to prevent contamination of the electrode or the blackening layer BL by contact. When forming the protective layer PL, for example, an acrylic UV-curable pressure-sensitive adhesive sheet was cut out to a size capable of protecting the electrode and laminated. Then, about 1000 mJ of UV light was irradiated to the UV curable adhesive sheet, and the UV curable adhesive sheet was hardened. Thereby, the upper part of the sensor including the electrode and excluding the connection terminal was covered with the protective layer PL.

[Example 2]

The blackening process of Example 1 was changed into the substitution blackening process, the conditions other than that were carried out similarly to Example 1, and the electrode which has blackening layer BL of Example 2 was obtained. Specifically, copper on the surface of the copper electrode was substituted for palladium (Pd) and attached thereto. At this time, the PET sheet having the electrode pattern described above was immersed in a hydrochloric acid solution containing Pd in a range of 100 ppm or more and 500 ppm or less. And, when the color of the electrode pattern was changed to blue, the reflectance was less than 20% in the visible region (400 nm or more and 780 nm or less), and the surface resistivity could be suppressed to 1 Ω/□ or less. Also in this case, the thickness of blackening layer BL was about 0.2 micrometer. Also from these results, in reducing the increase in the resistance value in the electrode, the treatment time for the sulfurization treatment is preferably in the range where the thickness of the blackening layer BL is 0.2 µm or less, and the surface of the electrode pattern shows blue. range is preferred.

In addition, as described above, as the line width of the electrode pattern decreases, the shape of the electrode pattern exhibits a rounded fish cake shape, and in the electrode pattern, it becomes difficult to distinguish between the side surface and the top surface. Therefore, the state in which the thickness of blackening layer BL is 0.2 micrometer shows the state in which the surface other than a bottom surface is covered with thickness of about 0.2 micrometer in an electrode pattern.

Table 1 shows the measurement results of the reflectance of an untreated stripe-shaped electrode that has not been subjected to blackening treatment, the electrode reflectance after the blackening treatment of Example 1, and the electrode reflectance after the blackening treatment of Example 3 for representative wavelengths.

As Table 1 shows, the reflectance of the untreated substrate increases at 550 nm or more, but this reflects the metallic properties of copper, indicating that the reflection from the glossy surface of copper is significant. The reflectance of this part is significantly reduced by the sulfidation blackening process and the substitution blackening process, and in the sulfidation blackening process and the substitution blackening process, it is suppressed to 15 % or less. In addition, generally, it is sufficient that such a reflectance is less than 20 %. Moreover, according to the sulfurization blackening process and the substitution blackening process, it was demonstrated that the reflectance falls large also on the short wavelength side.

[Example 3]

The blackening process of Example 1 was changed to the metal plating (Ni, Cr) process, the conditions other than that were carried out similarly to Example 1, and the electrode which has blackening layer BL of Example 3 was obtained. According to the electrode obtained by the metal plating (Ni, Cr) treatment, the reflectance in the visible region (400 nm or more and 780 nm or less) is suppressed compared to the electrode to which blackening treatment is not given, but the reflectance is less than 20%, and the surface It was confirmed that it was difficult to satisfy both of those having a resistivity of 1 Ω/square or less as in Examples 1 and 2.

[Example 4]

The blackening process of Example 1 was changed into the roughening blackening process, the conditions other than that were carried out similarly to Example 1, and the electrode which has blackening layer BL of Example 3 was obtained. According to the electrode obtained by the roughening blackening process, although the reflectance in a visible region (400 nm or more and 780 nm or less) is suppressed compared with the electrode to which blackening process is not given, a thing of less than 20% of reflectance, and a surface resistivity of 1 ohm/square It was confirmed that it is difficult to satisfy both of the following as in Example 1 and Example 2.

In addition, in the blackening treatment or substitution blackening treatment that satisfies both of a reflectance of less than 20% and a surface resistivity of 1 Ω/□ or less, the thickness of the blackening layer BL on the copper surface was in the range of 0.2 μm or less. And in the structure in which the thickness of blackening layer BL became larger than 0.2 micrometer, it was also confirmed that either a reflectance of less than 20 % and a surface resistivity of 1 ohm/square or less were not satisfied.

On the other hand, in metal plating or roughening blackening process, in order for reflectance to be 20% or less in the whole visible region (400 nm or more and 780 nm or less), the film thickness of blackening layer BL is thickened compared with sulfurization blackening process or substitution blackening process. It was unavoidable, and it was confirmed that the surface resistivity eventually became high. Moreover, the tendency for blackening layer BL to become weak and to fall off easily was confirmed, so that blackening layer BL was thick. Since there is a possibility that the blackening layer BL which fell off may be visually recognized as a foreign material or it may cause a short circuit, it is unpreferable from such a viewpoint. In addition, such drop-off|omission was not confirmed about the sulfurization blackening process or substitution blackening process.

[Example 5]

An example of the formation of the insulating resin layer 31I in FIG. 10 will be described.

After forming the electrode group extending in one direction, the insulating resin layer 31I was formed as follows. As the insulating material, an acrylic UV curable pressure-sensitive adhesive sheet having a dielectric constant of 2 or more and 4 or less and high light transmittance was used.

An acrylic UV curable adhesive sheet was cut out to a size capable of protecting the electrode group and laminated. Then, about 1000 mJ of UV light was irradiated to the UV curable adhesive sheet, and the UV curable adhesive sheet was hardened. As a result, the insulating resin layer 31I was formed in a predetermined portion of the electrode group.

After attaching a copper foil of the same thickness so as to cover the entire base material from above the insulating resin layer 31I, etching was performed again to form another electrode group orthogonal to the electrode group as the lower layer of the insulating resin layer 31I. After that, for each of the electrode group that is the lower layer of the insulating resin layer 31I and the electrode group that is the upper layer of the insulating resin layer 31I, blackening treatment was collectively performed at a portion visually recognized in a plan view. The blackening process may be divided into two times for every one electrode group, and you may perform it.

[Substitution blackening treatment]

Then, the Pd substitution process which is a preferable process among blackening processes is demonstrated below.

As mentioned above, sulfurization blackening process, substitution blackening process, oxidation blackening process, plating blackening process, and roughening blackening process are mentioned to the blackening process which is a process for fixing black to the surface of an electrode pattern. Among these, plating blackening process and roughening blackening process have the tendency for the resistance value of blackening layer BL to become high compared with sulfurization blackening process and substitution blackening process. Further, in the plating blackening treatment, since the temperature required for the plating solution is 80° C. or higher, the damage to the substrate immersed in the plating solution is large compared with other treatments.

Moreover, in the oxidation blackening process, since formation of blackening layer BL advances to terminals, such as a pad, which connect the exterior of the sensor body 20 and an electrode, the contact resistance value of the exterior of the sensor body 20 and an electrode tends to become high. has a In addition, in the blackening treatment, the blackening layer BL tends to have a needle-like shape, and although it is harder than the plating blackening treatment or the roughening blackening treatment, the blackening layer BL is peeled off or the line width of the electrode having the blackening layer BL is There is a fear that it becomes large.

In this regard, the substitution blackening treatment in which a metal atom on the surface of the electrode is replaced with another atom or a metal element on the surface of the electrode is replaced with a compound of another element not only suppresses the visibility of the electrode described above, but also It is also possible to achieve low resistance.

The atom to be replaced by the metal atom on the electrode surface is an atom having a lower ionization tendency than the metal atom, and may be an atom showing black on the electrode surface. For example, if the metal atom on the electrode surface has a configuration in which Cu is an atom, one element selected from the group consisting of Pd, Hg, Ag, Ir, Pt, and Au can be mentioned as an atom to be changed into a metal atom on the electrode surface. In addition, as a compound of another element that is changed to a metal element on the electrode surface, a compound of one element selected from the group consisting of Pd, Hg, Ag, Ir, Pt, and Au is exemplified. The temperature of the blackening treatment liquid containing such an element is 55° C. or less, and the time during which the substrate on which the electrode pattern is formed is immersed in the blackening treatment liquid is the time for the thickness of the blackening layer BL to be 0.2 μm or less, and is 120 sec or less. Moreover, it is preferable that the width change of the electrode pattern after blackening process is 0.3 micrometer or less for time during which the base material with an electrode pattern is immersed in blackening process liquid.

In particular, it is preferable that the atom to be converted into a metal atom on the electrode surface is Pd. Pd is generally cheaper than Au or Pt, ionization is easy compared with Au or Pt, and the ionized state is also stable. For example, it is possible to ionize Pt by dissolving Pt in aqua regia or by dissolving Pt chloride in dilute hydrochloric acid, but stabilizing the ionized state in this way is very difficult compared with Pd. In addition, Pd is easily ionized compared to Ir, and the ionized state is also stable. Further, the difference between the ionization tendency of Pd and the ionization tendency of Cu is larger than the difference between the ionization tendency of Ag and the ionization tendency of Cu.

When the atom to be converted into a metal atom on the electrode surface is Pd, the Pd concentration in the Pd solution serving as the blackening treatment liquid is preferably 100 ppm or more and 500 ppm or less, more preferably 200 ppm or more and 300 ppm. When the Pd concentration is 100 ppm or more and 500 ppm or less, the stagnation of the substitution reaction due to the low Pd concentration is suppressed, and the excessive progress of the substitution reaction due to the high Pd concentration is suppressed. Moreover, it is preferable that the pH in a Pd solution is 1.5 or more and 2.5 or less, More preferably, it is 1.8 or more and 2.1 or less. If the pH of the blackening treatment liquid is 1.5 or more and 2.5 or less, it is possible to stably maintain the ionization state in Pd in the blackening treatment liquid. Moreover, the temperature of the Pd solution is room temperature or more and 55 degrees C or less, Preferably it is 35 degrees C or more and 55 degrees C or less. If the temperature of the blackening treatment liquid is at least normal temperature and 55°C or less, it is also possible to stably maintain the ionized state of Pd in the blackening treatment liquid. And, the time for which the substrate on which the electrode pattern is formed is immersed in the Pd solution is 120 seconds or less, preferably 10 seconds or more and 120 seconds or less, and more preferably 45 seconds or more and 60 seconds or less.

[Example 6]

The Pd substitution process which is an example of the substitution blackening process mentioned above is demonstrated below.

Pd substitution treatment includes pretreatment, pretreatment water washing, blackening treatment, blackening water washing, and drying in this order. Table 2 shows an example of the conditions in pretreatment, pretreatment water washing, blackening treatment, blackening water washing, and drying.

In the pretreatment, the substrate on which the electrode pattern is formed is immersed in about 2% sulfuric acid by a dip method. The treatment temperature in the pretreatment is room temperature, and the time for the electrode pattern to be immersed in sulfuric acid is 20 seconds or more and 60 seconds or less. In the pretreatment water washing, the electrode pattern after the pretreatment is washed with water by a spray method. The treatment temperature in the pretreatment water washing is normal temperature, and the time washed with water is 20 seconds or more and 40 seconds or less.

In the blackening process, the electrode pattern after pretreatment water washing is immersed in the blackening process liquid which is a preparation liquid by a dip method. The blackening treatment liquid contains hydrochloric acid and palladium chloride, and contains an inorganic compound and a nitrogen-based organic compound as components other than these. The pH in the blackening treatment liquid is 1.99, and the palladium concentration in the blackening treatment liquid is 250 ppm. In addition, the temperature of the blackening treatment liquid is 45 degreeC, and the time for which an electrode pattern is immersed in this blackening treatment liquid is 45 second or more and 60 second or less.

In blackening water washing, the electrode pattern after a blackening process is washed with water by a spray system. The treatment temperature in the pretreatment water washing is normal temperature, and the time washed with water is 20 seconds or more and 40 seconds or less.

In drying, 70 degreeC hot air is sprayed to the electrode pattern after blackening water washing as an air knife for 20 second.

Then, each of the three electrode patterns having different line widths was subjected to the Pd substitution treatment described above. As a result, in any electrode pattern, it was confirmed that the position of blackening layer BL was all parts other than the surface which opposes a base material among the surfaces which an electrode pattern has. That is, it was confirmed that the blackening layer BL was formed in the side surface or the top surface in an electrode pattern when the surface which opposes a base material among the surfaces which an electrode pattern has is a bottom surface.

Table 3 shows the difference between the resistance value in the electrode pattern before the Pd replacement treatment and the resistance value in the electrode pattern after the Pd replacement treatment. Table 4 shows the difference between the line width in the electrode pattern before the Pd replacement treatment and the line width in the electrode pattern after the Pd replacement treatment. Table 5 shows the difference between the contact resistance value of the electrode pattern before the Pd replacement treatment and the contact resistance value of the electrode pattern after the Pd replacement treatment with respect to the contact resistance value between the outside of the sensor body and the electrode pattern. In addition, the difference between the reflectance in the electrode pattern before Pd substitution process and the reflectance in the electrode pattern after Pd substitution process is shown in Table 6 and FIG. The line width before Pd substitution treatment in pattern A is 4.35 μm, the line width before Pd substitution treatment in pattern B is 3.95 μm, and the line width before Pd substitution treatment in pattern C is 3.56 μm.

As Table 3 shows, in any pattern from pattern A to pattern C, the rate of increase of the resistance value in the first electrode is 4.0% or more and 9.1% or less, and the rate of increase in the resistance value in the second electrode is It was confirmed that they were 5.9% or more and 14.8% or less. That is, according to the Pd substitution process mentioned above, it was confirmed that the increase rate of the resistance value in before and behind a Pd substitution process was 20 % or less.

As Table 4 shows, the amount of change ΔW of the line width by the Pd substitution treatment described above was 0.18 µm, 0.07 µm, and 0.12 µm, and it was confirmed that all of them were 0.3 µm or less.

As Table 5 shows, the contact resistance value RA after the Pd substitution treatment described above was confirmed when it was higher and lower than the resistance value before the Pd substitution treatment, and it was confirmed that it was a low resistance value of 0.1 Ω or less in either case.

As Table 6 shows, the reflectance after the Pd substitution treatment described above is a substantially constant value in the wavelength region of 400 nm or more and 600 nm or less, and in the wavelength region of 600 nm or more and 780 nm or less, the longer the wavelength, the higher the tendency. showed In the wavelength region of 400 nm or more and 780 nm or less, suppression of the reflectance after such Pd substitution treatment was larger than that before Pd substitution treatment. And, as the solid line in Fig. 13 shows, the reflectance after the Pd substitution treatment was confirmed to be 20% or less at any wavelength in the wavelength region of 400 nm or more and 780 nm or less. As the broken line in Fig. 13 shows, compared with the reflectance before the Pd substitution treatment, a large decrease was confirmed in the reflectance after the Pd substitution treatment in the wavelength region of 600 nm or more and 780 nm or less. Moreover, in the wavelength region of 400 nm or more and 600 nm or less, the reflectance was 10 % or less, and it was confirmed that the color of the electrode pattern after a blackening process was tinged strongly from blue to black.

As mentioned above, according to the said embodiment, the effect enumerated below is acquired.

(1) The blackening layer BL is located on the side seen in the oblique direction among the surfaces of the electrode. Moreover, the position of the blackening layer BL also reaches the site|part other than a side surface among the surfaces which an electrode has. Therefore, it is possible to suppress the reflective luster peculiar to the metal on the side surface of the electrode, and it is also possible to retain the low resistance value of the metal other than the surface layer. As a result, it is possible to reduce the increase in the resistance value of the electrode and suppress the visibility of the electrode.

(2) Since the surface resistivity of blackening layer BL is less than 1 ohm/square, also in the electrode which has blackening layer BL on a side surface, it is suppressed that the resistance value of an electrode becomes high by formation of blackening layer BL.

(3) Since the reflectance of blackening layer BL is less than 20 % in the visible region which is 400 nm or more and 780 nm or less, the effect described in said (1) becomes more remarkable.

(4) Since the thickness of the blackening layer BL is 0.2 µm or less, if the gap between adjacent electrodes is 1 µm or more, the gap between adjacent electrodes is filled by the blackening layer BL or the blackening layer between adjacent electrodes Shorting through BL is sufficiently suppressed.

(5) Since blackening layer BL is formed by substitution blackening process, compared with plating blackening process or roughening blackening process, it can suppress that the resistance value of an electrode improves. Moreover, compared with a sulfurization blackening process, it is also suppressed that blackening layer BL peels off from an electrode.

In addition, the said embodiment can also be changed suitably as follows and can also be implemented.

- Thickness of blackening layer BL may be larger than 0.2 micrometer, and what is necessary is just the range from which the detection precision calculated|required of the resistance value requested|required of an electrode, and a touchscreen by extension is obtained.

- The reflectance of the blackening layer BL may be 20 % or more in the visible region of 400 nm or more and 780 nm or less, and it is sufficient that the reflectance is lower than the reflectance of the conductive film before blackening layer BL is formed.

- The surface resistivity of blackening layer BL may be 1 ohm/square or more, and similarly to the thickness of blackening layer BL, the resistance value calculated|required of an electrode, by extension, the detection precision calculated|required of a touchscreen should just be a range obtained.

BL: blackening layer
W31 : electrode width
W31B : Bulk Width
10: display panel
20: sensor body
22: cover layer
31DP: first electrode
31KS : Top
33SP: second electrode

Claims (9)

a substrate having a first surface;
A plurality of electrodes positioned on the first surface,
Each of the plurality of electrodes,
a bottom surface in contact with the first surface;
a top surface exposed from the first surface and facing the bottom surface;
a side surface exposed from the first surface and connecting the bottom surface and the top surface;
It is a blackening layer which is a surface layer, and at least one of the said bottom surface and the said top surface, and the said side surface are provided with the said blackening layer which comprises the surface of the said blackening layer,
The surface resistivity of the blackening layer is less than 1Ω / □ of the touch sensor substrate. According to claim 1,
The thickness of the blackening layer is 0.2 μm or less of the touch sensor substrate. 3. The method of claim 1 or 2,
The reflectance of the blackening layer is less than 20% in the visible region of 400 nm or more and 780 nm or less. a sensor base including a plurality of first electrodes, a plurality of second electrodes, and a transparent dielectric layer sandwiched between the plurality of first electrodes and the plurality of second electrodes;
a cover layer covering the sensor body;
It is a touch panel having a peripheral circuit for measuring the capacitance between the first electrode and the second electrode,
The touch panel includes the touch sensor substrate according to claim 1 or 2, and at least one of the plurality of first electrodes and the plurality of second electrodes is the first surface of the touch sensor substrate. A touch panel, characterized in that the plurality of electrodes located in the. a display panel for displaying information;
a touch panel that transmits the information displayed by the display panel;
and a driving circuit for driving the touch panel;
The said touch panel is a display apparatus which is the touch panel of Claim 4. A step of forming a plurality of metal electrode patterns on a substrate having a first surface, wherein each of the plurality of electrode patterns includes a bottom surface in contact with the first surface, a surface exposed from the first surface, and the bottom surface; The process comprising: an opposed top surface; and a side surface exposed from the first surface and connecting the bottom surface and the top surface;
A touch comprising a step of subjecting each of the plurality of electrode patterns to a blackening treatment, either of a sulfurization blackening treatment and a substitution blackening treatment, to change at least one of the bottom surface and the top surface and the side surface to a blackening layer which is a surface layer A method for manufacturing a sensor substrate. 7. The method of claim 6,
In the blackening treatment, the electrode pattern is immersed in a blackening treatment liquid, which is a solution containing Pd ions, and a substitution reaction between a metal constituting the electrode pattern and the Pd ion is performed to form a blackening layer in the electrode pattern. blackening treatment,
The temperature of the blackening treatment liquid is 55 ° C. or less,
The time for immersing the electrode pattern in the blackening treatment liquid is 120 seconds or less, and the thickness of the blackening layer is set to a length of 0.2 µm or less. 8. The method of claim 7,
The temperature of the blackening treatment liquid is 35 ° C or more and 55 ° C or less,
Pd concentration in the blackening treatment liquid is 100 ppm or more and 500 ppm or less,
pH in the said blackening treatment liquid is 1.5 or more and 2.5 or less,
The time for which the electrode pattern is immersed in the blackening treatment liquid is 10 seconds or more and 120 seconds or less, and the thickness of the blackening layer is set to a length of 0.2 µm or less. 9. The method of claim 8,
The time during which the electrode pattern is immersed in the blackening treatment liquid is a method of manufacturing a touch sensor substrate in which a change in the line width of the electrode pattern before and after the blackening treatment is set to a length of 0.3 μm or less.

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